depends on the length of the sides. A hackamore is basically a tool for riding bitless, but can also be used in combination with a snaffle. A hackamore can be quite sharp because of the leverage and the pressure on the nose and chin. If a curb chain is used, the Hackamore is even sharper.
It is very important that the noseband of the hackamore is placed correctly. The hackamore is not suitable for inexperienced riders or horses.